Field
The present disclosed embodiments relate generally to computing devices, and more specifically to control of power to processors.
Background
Computing devices including devices such as smartphones, tablet computers, gaming devices, and laptop computers are now ubiquitous. These communication devices are now capable of running a variety of applications (also referred to as “apps”) and many of these devices include processors to process tasks that are associated with apps. In many instances, multiple cores are integrated as a collection of processor cores within a single functional subsystem. It is known that the processing load on a mobile device may be apportioned to the multiple cores. As an example, for load balancing purposes, a processing task may be migrated from one core to another core. In many existing devices multiple cores operate at the same frequency; thus a particular task may be migrated from one core to another core without substantially affecting what the user experiences because the task is processed at the same frequency regardless of the core.
In a system with a synchronous multi-core processor, in which all cores are powered by the same voltage supply, it is necessary for the voltage of the supply to be high enough to account for losses (e.g., voltage drops in a power distribution network on the board and in the system on a chip (SoC)) as well as noise so that all cores can operate successfully at the same time. But this voltage may be conservatively kept too high in situations where not all of the cores are active, which leads to unnecessary, additional power consumption.